1. Technical Field
The present invention relates to a liquid ejecting head including a wiring substrate on which wires to be connected to a driver IC have been formed and a method of manufacturing the liquid ejecting head.
2. Related Art
As liquid ejecting apparatuses including liquid ejecting heads, for example, there exist image recording devices such as ink jet printers, ink jet plotters and the like, however, recently, liquid ejecting apparatuses have been applied to various manufacturing devices by utilizing their advantage of being able to make a minute amount of liquid precisely land onto a designated position. For example, liquid ejecting apparatuses have been applied to display manufacturing devices that manufacture color filters of liquid crystal displays and the like, electrode forming devices that form electrodes of organic electroluminescence (EL) displays, field emission displays (FEDs) and the like, and chip manufacturing devices that manufacture biochips. In addition, a recording head for image recording devices ejects liquid ink, and a color material ejecting head for display manufacturing devices ejects solutions of individual color materials of red (R), green (G), and blue (B). Moreover, an electrode material ejecting head for electrode forming devices ejects a liquid electrode material and a bioorganic matter ejecting head for chip manufacturing devices ejects a solution of bioorganic matter.
The above-described liquid ejecting heads are formed by stacking a pressure chamber forming substrate formed of pressure chambers that communicate with nozzles, piezoelectric elements (a type of driver element) that cause a change in pressure in the liquid inside the pressure chambers, a sealing plate which is arranged so as to be separated at a distance from the piezoelectric elements, and the like. The above-described piezoelectric elements are each driven by a driving signal that is supplied from a driver IC. This driver IC, in the related art, is arranged outside the liquid ejecting head. For example, there is known a liquid ejecting head in which a driver IC is provided on a flexible substrate that connects to the liquid ejecting head (for example, JP-A-2011-115972).
To date, with the reduction in the size of liquid ejecting heads, techniques for joining a driver IC onto a sealing plate that covers piezoelectric elements have been developed. In such a structure, a wire that supplies electrical power to the driver IC is formed on a surface on one side (driver IC side) of the sealing plate. If, with nozzle densification, the number of nozzles increases, the electrical power supplied to the driver IC also increases. Consequently, reducing the electrical resistance (hereinafter simply called resistance) of the wire formed on the sealing plate has been considered. However, to date, when the width of the wire has been increased in order to lower the resistance of the wire, the wire area has become large. Consequently, it has been difficult to decrease the resistance of the wire without changing the size of the sealing plate.